vector trouble

Hallo,

I am having a problem with creating a vector that contains Triangles, which is a class I have made myself.

Code:

---

#ifndef INPUT_H
#define INPUT_H


#include "CommonMath.h"    // Math stuff
#include "Primitives.h"    // Needed for Triangle
#include <vector>          // For easy use of dynamic arrays

// Create an array of triangles after reading the vertex
// cordinates from a file
std::vector<Triangle> loadFromFile(std::string FileName);

#endif

---

As you see the whole thing is really simple, but still it does not work.
The error I get is : `Triangle' was not declared in this scope

Thanks

Well, was it? Perhaps it's in a namespace.

What's in Primitives.h?

Quote:

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What's in Primitives.h?

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Code:

---


class Primitive
{
      public:
            Primitive(std::string n = "DefaultName");
            //~Primitive();
           
            void setName(std::string n); 
            virtual std::string getName();
           
            void setMaterial(Material m);
            virtual Material* getMaterial();
           
            virtual Vector3D getPos() = 0;
           
            virtual result intersectionTest(Ray r) = 0;
           
      private:
              //type
              std::string name;
              Material material;
};

// The subclass for a sphere
class Sphere : public Primitive
{
      public:
            Sphere(Vector3D pos, float r);
            float getRadius();
            float getRadiusSqr();
           
            void setPos(Vector3D pos);
            Vector3D getPos();
           
            result intersectionTest(Ray r);
      private:
              float radius;
              Vector3D position;
};


class Triangle : public Primitive
{
      public:
            Triangle(Vector3D _v1, Vector3D _v2, Vector3D _v3);
            result intersectionTest(Ray r);
           
            Vector3D getPos();
      private:
              // The three vertexes
              Vector3D v1;
              Vector3D v2;
              Vector3D v3;
};

// mesh class
class Mesh : public Primitive
{
      public:
            Mesh(std::string fName);
           
            result intersectionTest(Ray r);
            Vector3D getPos();
            // loadFromFile();
            // bounding box
            // getNormalX(int triangle)
           
           
      private:
              // triangleList class Triangle?
              // No of triangles
};

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thats what I have in the file and as you see its here Triangle is declared. What do you mean about the namespace thing?

Thanks

May-be you should also include string?
Are you sure there are no circular dependencies?

Quote:

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May-be you should also include string?

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Yes, you are right, but it works as it is already included in CommonMath and Primitives.h

Quote:

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Are you sure there are no circular dependencies?

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Sorry to ask, but that is that?

Does your .h file have an #ifndef guard? Did you possibly screw up and use #ifdef instead of #ifndef?

Quote:

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Does your .h file have an #ifndef guard? Did you possibly screw up and use #ifdef instead of #ifndef?

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No, and also the classes from Primitive.h is used in other files without trouble.

Can it have something to do with Triangle being a subclass of Primitive?

Quote:

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Originally Posted by h3ro

No, and also the classes from Primitive.h is used in other files without trouble.

Can it have something to do with Triangle being a subclass of Primitive?

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What .cpp file is this loadFromFile() function declared in? Are all the proper headers being included there?

If you are willing to post an archive containing everything, I'll have a look.

EDIT: Sometimes this message arises because of a missing semicolon at the end of a struct or class declaration.

Quote:

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If you are willing to post an archive containing everything, I'll have a look.

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Thats very nice of you :)
http://rapidshare.com/files/29263271/Raytracer.rar.html

Primitives.h includes input.h
input.h includes Primitives.h

The error is happening because input.h is being included into primitives.h.

But I need them to know about each other. Is there a workaround for this?

Why do you need Primitives.h to know about Input.h? (I didn't look in your archive.)

In general, use a forward declaration inside a header file rather than an include when you can.

Well, if they really need to know about each other, then there's a basic design problem, but I don't think that's the case...

• Does primitives.h really need input.h; or does only primitives.cpp need to know about input.h? You should shoot for a few nested-headers as neccesary.
• If I understand correctly... the problem is in class Mesh. It's perfectly fine to put Mesh off in a class on it's own, removing primitives.h's dependency on input.h

My general rule is that a header should only include another header if the former header absolutely REQUIRES the full definition of a type provided by the other header. If the interface specified by the header file requires only the NAME of a type, but doesn't need to know its definition, then the header can just forward-declare the type itself. This can end up saving you a LOT of compile time, because headers don't have to get parsed over and over again in each module which only references a type incidentally (e.g. via a pointer, without dereferencing).

One approach is to make pairs of header files. One header forward-declares the types, the other defines them.

Code:

---

/* File: primitive_forward.h */

class Primitive;

---

Code:

---

/* File: primitive.h */

#include "primitive_forward.h"

class Primitive
{
    /* Class is defined here */
};

---

Then, you can choose to include only primitive_forward.h in modules which only reference pointers to Primitive. For modules that actually need the definition of Primitive, they include primitive.h.

It looks unnecessary to include primitive_forward.h from primitive.h, and strictly, it IS unnecessary, but it serves a purpose. If you alter the nature of Primitive, say, by making it a typedef of another type, and you forget to change it in both files, the compiler will give an error, instead of silently compiling broken code.

I know that might not make much sense to you yet, but eventually it will.

Thanks for the help everyone, it works now (Did it the easy way, by including primitives.h in input.cpp)

brewbuck: That made perfectly sense, and thanks for the tip. Ill do that when I redesign my simple raytracer. I have already restarted it ones, but as I learn more and more I see errors in the base of the programs which need to be changed, so back to the start.

Just a question to the ones who looked at the source code, is my programing hard to read, or did it go ok?

Edit: Does anyone here written a raytracer before? I have a few questions that I would ask, but not sure if this forum is appropriate for that?

Thanks once again to the members of this forum for outstanding help.

I believe some people have written ray tracers. Ask your questions concerning them in the Game Programming forum.

Quote:

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Originally Posted by h3ro

Just a question to the ones who looked at the source code, is my programing hard to read, or did it go ok?

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I think it's fine. I wouldn't waste an indent level on "public" and "private" though :)

I also see you're using abstract virtuals appropriately. Cool beans. Good design so far.

A new question:

When I try to add "std::vector <Triangle> triangleList;" as a public in my mesh class I get this error:
from main.cpp In file included from Scene.h:6, from main.cpp
using-declaration for non-member at class scope

Does that mean that the variable name is already taken? (Its not, as there is no such variable in scene.h)

Code:

---

// mesh class
class Mesh : public Primitive
{
      public:
            Mesh(std::string fName);
           
            result intersectionTest(Ray r);
            Vector3D getPos();
            // loadFromFile();
            // bounding box
            // getNormalX(int triangle)
           
            std::vector <Triangle> triangleList;  // <--- Error
      private:
              // triangleList class Triangle?
              // No of triangles
};

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It's good code. There's some things I would do differently... like the 'result' class is a bit of a cludge.

Code:

---

result Sphere::intersectionTest(Ray r)

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Also, having a 'Point' class is bad. It doesn't help you do anything you couldn't do using a Vector3D, and in fact you have to convert it back to a Vector3d to do anything mathematically interesting.

If you want to distinguish that a certain variable is a point, you should do so by putting the word 'point' in the variable's name, not making a new class.

And yea, I've written a ray tracer before. Thanks for the opportunity to plug my pictures =)
http://questionc.com/graphics/

Quote:

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Also, having a 'Point' class is bad. It doesn't help you do anything you couldn't do using a Vector3D, and in fact you have to convert it back to a Vector3d to do anything mathematically interesting.

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I know, but when I started writing this thing I had no knowledge of how to do it, so I tried to implement as much as possible from a book I bought (Physically based rendering), and there they uses Point for a few things. I later found out that this made things much harder, so I decided to make a easy way of fixing it instead of rewriting so much.

Quote:

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And yea, I've written a ray tracer before. Thanks for the opportunity to plug my pictures =)

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Nice work! I see you started with global illumination, was it hard to implement? So far I only have diffuse lighting as you probably saw

Right now I'm thinking of removing all the primitive classes and only have a mesh class. Its so much more fun to have some real objects instead of just spheres. But I plan to keep the sphere (and add at least box) code and use it for bounding box calculations to speed it all up.

What do you think of doing mesh collision like this:

Code:

---

intersectionTest(Ray r)
{
      if (boundingBoxTest == 1)
            Check each of the triangles
            Return the closest one
}

---

I think that will save a lot of calculation time.

Btw: Are you still working on your raytracer?

That's standard procedure to shortcut collision tests. So yeah, it's a good thing.

Another standard procedure is to sort all objects by location, e.g. in an octree. This way, you can quickly kick out a lot of elements. (Basically, everything that is not in the same subtree.)

Quote:

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Another standard procedure is to sort all objects by location, e.g. in an octree. This way, you can quickly kick out a lot of elements. (Basically, everything that is not in the same subtree.)

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Thats nice. Ive seen that octrees often pops up when I read about raytracing. Looks like a nice concept, but I have a lot of other stuff to add first. This is the biggest program I have made so far so I'm not trying to create a kick-ass raytracer, just trying to learn stuff. If I get my mesh class to work so that I can load objects from my 3d program Im more than happy.

What kind of information would I need to export?
I know I will need the three vertexes of all triangles in the mesh, and probably the normal. Is there any other key parts? Im not going to export materials or UVs.

I know there are a lot of formats that I could try to use, but I kind of like to make my own, if its not to complicated

Quote:

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Originally Posted by h3ro

I know, but when I started writing this thing I had no knowledge of how to do it, so I tried to implement as much as possible from a book I bought (Physically based rendering), and there they uses Point for a few things. I later found out that this made things much harder, so I decided to make a easy way of fixing it instead of rewriting so much.


Nice work! I see you started with global illumination, was it hard to implement? So far I only have diffuse lighting as you probably saw

Right now I'm thinking of removing all the primitive classes and only have a mesh class. Its so much more fun to have some real objects instead of just spheres. But I plan to keep the sphere (and add at least box) code and use it for bounding box calculations to speed it all up.

What do you think of doing mesh collision like this:

Code:

---

intersectionTest(Ray r)
{
      if (boundingBoxTest == 1)
            Check each of the triangles
            Return the closest one
}

---

I think that will save a lot of calculation time.

Btw: Are you still working on your raytracer?

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• You can't remove all your primitive classes... even the Mesh class depends on Triangle's methods.
• I pretty much had GI done, Global Illumination is relatively simple compared to the other problems in Raytracing. It just takes a sick amount of time to process. The grainy picture on my page represents maybe 5 minutes worth of processing (I was impatient). I like that image though.
• The Raytracer images are from about five years ago, I'm not working on it anymore. It was part of an independent study in College and I lost the sources during a botched OS upgrage.
• When exporting a triangle, only export the three vertices. The Normal should be computed ny the constructor.